Tool for cutting insulation on electric conductors



March 1948 'G. G. Gl VE NS I 2,437,514

TOOL FOR CUTTING INSULATION 0N ELECTRIC CONDUCTORS Filed Jan. 23, 1946 2 Sheets-Sheet l 3 2 z 3 I: 5' u 25 i5 20 a] Glen/772 Inventor and pally 25 M5 are 9, 1948. G. G. GIVENS I 2,437,514

TOOL FOR CUTTING INSULATION 0N ELECTRIC CONDUCTORS I Filed Jan. 23, 1946 2 Sheets-Sheet 2 Z .6. F .27 9 g g I 6 lm/enQto) W M ays Patented Mar. 9, 1948 TOOL FOR CUTTING INSULATION ON ELECTRIC CONDUCTORS Glenn G. Givens, Newport News, Va. Application January 23, 1946, Serial No. 642,809

3 Claims.

The present invention relates to a new and useful improvement in cutting tools for use on electric conductors for cutting the insulation covering the same and the invention has for its P y object to provide a tool of this character including a cutter mounted at the end of the tool and projecting into a transverse opening therein for cutting the insulation covering an electric conductor when positioned in said opening. v

An important object of the invention is to provide means for mounting the cutter in the tool for adjustment whereby the insulation covering may be out either longitudinally or circumferentially of the conductor.

A still further object of the invention is to provide a, slidable mounting for the cutter adapted for engagement by the thumb of a person for exerting the necessary pressure against the insulation covering during the cutting action.

Another object of the invention is to provide a hand-gripping body having cutters of duplicate construction mounted in each end thereof and associated with transverse openings in the body of different sizes to accommodate wires of different diameters.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming part hereof, wherein; like numerals refer to like parts throughout, and in which:

Figure 1 is a side elevational view.

Figure 2 is a similar view taken at right angles to Figure 1 and showing the transverse openings in the opposite ends of the body of the tool.

Figure 3 is a longitudinal sectional view taken substantially on a line 3-3 of Figure 1.

Figure 4 is an enlarged longitudinal sectional view of one of the caps and cutter mounted there- Figure 5 is a transverse sectional view taken on a line 5-5 of Figure 3.

Figure 6 is a side elevational view of the tubular blade holder sleeve.

Figure 7 is a longitudinal sectional view taken on a line 1-1 of Figure 6.

Figure 8 is an elevational View of the inner end of the blade holder sleeve.

Figure 9 is a longitudinal sectional view of the adjustable blade holding member.

Figure 10 is a, similar view taken on a line Hl-l 0 of Figure 9.

Figure 11 is an end elevational view of the lower end of the blade holding member.

Figure 12 is a perspective view of the blade.

Figure 13 is a side elevational view of the retaining bushing for the blade, and W Figure 14 is a side elevational view of the adlusting screw for the blade.

Referring now to the drawings in detail wherein for the purpose of illustration I have disclosed a preferred embodiment of the invention. The numeral 5 designates the elongated body of the tool which is of cylindrical construction and formed with an enlarged end 6 at one end thereof.

A transverse opening 'I is formed in the enlarged end portion of the body and a similar transverse opening 8 is formed near the opposite end of the body, the openings being adapted to receive electric conductors 9 therein of different diameters, the conductors being of the usual type provided with a natural or synthetic rubber insulation covering l0.

Caps l l and I2 are telescopically mounted on the opposite ends of the body, each cap being provided with a cutter designated respectively at l3 and Hi, the cutters being of identical construction and accordingly a detailed explanation of one will suffice for both.

The cutter embodies a cutter holding sleeve l5 having one end projecting through the top of the cap H and welded or otherwise suitably secured thereto as indicated at 15. The outer end of the sleeve is internally threaded as shown at H for threaddly receiving an adjusting screw is therein.

The inner end of the sleeve is closed as indicated at l9 and formed with a transverse slot 20 and in which a fiat blade 2| is slidably received. One end of the blade is pointed as indicated at 22, while the other end of the blade is formed with a cross head 23 which has its ends projecting outwardly from the opposite side edges of the blade.

A bushing25 is positioned in the inner end of the sleeve I5 with one end resting on the closed end l9 and with notches 26 formed in its other end at diametrically opposite sides receiving the ends of the cross head 23.

A tubular blade holder 21 is slidably mounted in the sleeve Hi, the lower end of the blade holder being formed with a bifurcated extension 28 of reduced diameter and in which the inner end of the blade M is received.

The inner end of the adjusting screw i8 is formed with a reduced extension 29 having an external annular groove 30 formed therein for receiving a set-screw 3| threaded through an opening 32 in one side of the tubular holder 21. The extension 29 on the inner end of the adjust- 3 ing screw I8 is mounted for rotation in the tubular blade holder 21 during the rotation of the screw during its adjustment while the blade holder 27 is held against rotation by the blade in the slot 29 of the sleeve I5. The inner end of the sleeve I i slidably received in a bushing 33 positioned in a longitudinal opening 34 in the end of the body 5, the bushing being secured against the rotation bymeans' of ai set' screw 40. A spring actuated plunger 35'is mounted in a transverse opening 36 in the body and having a tip 35a projected through an opening 3'! in one.

side of the bushing by means of a coil spring-3B... The spring i held in the opening 36bymeans3off a screw 39. The tip 35a is projectedinto longitudinal grooves 42 formed in the sides of: the:

sleeve I5 at angles of 90 degrees to, retain the.

sleeve in rotatably adjustedposition" in'thebusli ing whereby to position the blade 2| either transversely or longitudinally'with respect to the cable for cutting the cableeither longitudinally or. circumferentially.

The adjusting screw I8 is.formed"with..a bore 43 in its outer end in whicha-plug. 44. isfixedly secured.- The inner endof. the. plug is..formed with a transverse groove. adapted to. receive. a cross head-ficarried at theinner endofl a stem 41 slidably mounted 'in. the plug: andhaving. a knob 48 secured to 'its outer end. By pullingthe knob outwardly to seat thecrosshead 46-.in.the groove 45 the screw may be rotated to adjust the screw I 8. in-the sleeve: I5 andthusregulate the cutting depth of the blade 21.

In the operation of the device the. blade 2I, bushing 25, blade holder- 21 and. adjusting screw I Bare mounted in assembled. relation inthe sleeve I 5-in the manner as illustrated-in Figure 4. of. the drawings with'the inner end of theblade-projecting from the inner end of the sleeve and the sleeve being carriedby the cap: I I;

The sleeve I5 andcap II are thenrotatably adjusted inthe. body so that the pointedend. of the blade will? extend either. longitudinally of the openingi or transversely thereof dependingupon the character of cut to be made in.-the-insu1a-tion I0; Where the insulation is to be cut longitudinally, the--cutter 21: ispositioned longitudinally in the opening and where a: circumferential out 1510 be formed in the insulation, the cutter is positioned transversely of the opening I; The sleeve I 5is secured in its adjusted-position-against rotation by means of spring projectedtip 35a on the plunger 35 engaged in the grooves. of the sleeve I5.-

The cutting tool is thenheld in the hand of a person with the thumb bearing against the. cap I I to-exert a. desired'pressure onthe blade H and by sliding the conductor 9 transversely of the body 5 the insulation will be cut longitudinally, 0r by'rotating the-conductor in the-opening I the 4 insulation will be cut circumferentially, the blade being adjusted in accordance with the character of the cut to be made in the insulation.

In view of the foregoing description taken in conjunction with the accompanying drawings it is believed that a clear understanding of the construction, operation and advantages of the device will be quite apparent to those skilled in the art. A more-detailed descriptionds accordingly deemed unnecessary.

It is to be understood, however, that even though there is herein shown and described a preferred embodiment of the invention the same is susceptible-tocertain changes fully comprebended by the spirit of the invention as herein describedzand'the scope of the appended claims.

I claim:

1-. A wire strippercomprising an elongated body havinga transverse opening adapted to receive an insulated wire therein, a sleeve slidably mounted in the body for longitudinal movement thereof, a blade holder mounted for longitudinal sliding movement in the sleeve, blade carried by the holder, and an adjusting screw threadedin the sleeve and'iconnected to the blade holder for. adjusting the blade relative to the wire.

2. A wire stripper comprising an elongated body having, a transverse opening adapted to receive an insulated wire therein, a sleeve slidably mounted in the body for longitudinal movement thereof, a blade holder. mounted for longitudinal sliding movement in the sleeve, a blade carried by the holder, an adjusting screw threaded in the sleeve and connected to the blade holder for adjusting the blade longitudinally in the sleeve relative to the'wire, and an interlocking manipulating member mounted'in the screw for sliding interlocking engagement therewith.

3. A wire stripper comprising an elongated body having a transverse opening adapted to receive an insulated'wire therein, a sleeve slidably mounted in the body for longitudinal movement thereof,

a blade holder mountedfor longitudinal sliding movementin the sleeve, 3, blade carried by the holder, an adjusting screw threaded in the sleeve and connected to the blade holder for adjusting theblade longitudinally in the sleeve relative to the wire, and a cap telescoping on the body and connected to the sleeve for subjecting the blade to manual cutting pressure,

GLENN G. GIVENS.

REFERENCES CITED The following references are of record in the 

